Advertisement
RCU power supply
The RCU can be powered from either an
auxiliary power supply or a solar panel
supply and incorporates a battery for
standby backup purposes when the supply is
absent. Refer to the Technical data on page
64 for specification of voltage ranges,
power consumption, etc.
Auxiliary power supply
The auxiliary power supply should be
connected into the terminal compartment
(refer to Figure 26: Auxiliary power cable
connection details on page 32) to a
dedicated set of terminals. There is a voltage
selector switch to select between 115 Vac
and 230 Vac supplies. The terminal
compartment also includes a fuse.
Optionally, the incoming supply can be
connected via a power supply isolation unit,
see section on Power supply isolation unit
on page 13.
Refer to section Auxiliary power supply
beginning on page 30 for safe installation
instructions.
Solar supply
Where a low-voltage auxiliary power supply
is not available, Siemens has a solar panel
option to provide charge to the batteries.
The solar panel is sized to provide adequate
charge for energy efficient radios and
modems in latitudes less than 45°. The
panel angle can be adjusted between two
settings to optimize performance for given
latitudes. The solar panel must be mounted
on the same power pole as the RCU, refer
installation details in the Solar panel supply
on page 33.
The solar panel is connected into the
terminal compartment to a dedicated set of
terminals as an alternative to the auxiliary
power supply. Siemens can assist with
determining the correct power rating of
solar panels or a suitable solar panel can be
supplied by Siemens.
The RCU monitors the solar supply in two
ways:
1. The RCU checks that each day there is
some voltage from the solar panel (even
on the most overcast day the solar panel
will have some output). This will detect
a solar panel that has been disconnected
or failed.
2. If there is insufficient sunlight during
the day, the solar panel may not be able
to fully recharge the battery on that day.
This is not a problem since the battery
will usually have sufficient power stored
to operate during periods of low
sunlight. However, over a period of days,
it is expected that the panel will fully
charge the battery. Accordingly, the RCU
checks that the solar supply has been
able to fully recharge the battery within
a specified number of days. If not, this
indicates that either the panel is
degraded in some way (for example,
covered in leaves or dust) or there has
been an exceptional run of bad weather.
The maximum time period for full
recharge is set in the RCU configuration
in RCU power supply settings starting on
page 68.
If either of these conditions occurs, then a
solar panel problem database point
(DPID_4) is set and is available for
transmission via the SCADA system.
A
B
Figure 13: Solar panel assembly
Item
A
B
C
C
Description
Bird roost guard
Mounting bracket
Solar panel
17
Advertisement
